R. D. Ferdman

Long-term project observations for project L133 semester 2026APRS_01

Marta Burgay, Andrea Possenti, Dick Manchester, Michael Kramer et autres

This project is to continue timing and profile studies of the first double-pulsar system, a unique laboratory for gravitational physics. Important results published in our 53-page Phys. Rev. X paper (2021) include the first measurements of higher-order light-propagation effects and of the …

it, au, de, us, gb (code pays fourni par la source)

The NANOGrav 12.5-year Data Set: Chromatic Noise Characterization & Mitigation with Time-Domain Kernels

Jeffrey S. Hazboun, Joseph Simon, J. G. Baier, Bjorn Larsen et autres

Pulsar timing arrays (PTAs) have recently entered the detection era, quickly moving beyond the goal of simply improving sensitivity at the lowest frequencies for the sake of observing the stochastic gravitational wave background (GWB), and focusing on its accurate spectral characterization. While …

The NANOGrav 12.5 yr Data Set: Probing Interstellar Turbulence and Precision Pulsar Timing with PSR J1903+0327

Abra Geiger, James M. Cordes, Michael T. Lam, Stella Koch Ocker et autres

Abstract Free electrons in the interstellar medium refract and diffract radio waves along multiple paths, resulting in angular and temporal broadening of radio pulses that limits pulsar timing precision. We determine multifrequency, multiepoch scattering times for the large dispersion measure millisecond PSR …

Searches for signatures of ultralight axion dark matter in polarimetry data of the European Pulsar Timing Array

N. K. Porayko, P. Usynina, Jorge Terol-Calvo, Jorge Martin Camalich et autres

Ultralight axionlike particles (ALPs) can be a viable solution to the dark matter problem. The scalar field associated with ALPs, coupled to the electromagnetic field acts as an active birefringent medium, altering the polarization properties of light through which it propagates. In …

de, it, es, co, fr, gb, pt, nl, cn, ie, pr (code pays fourni par la source)

Long-term project observations for project P455 semester 2025OCTS_05

Marta Burgay, Andrea Possenti, Dick Manchester, Michael Kramer et autres

This project is to continue timing and profile studies of the first double-pulsar system, a unique laboratory for gravitational physics. Important results published in our 53-page Phys. Rev. X paper (2021) include the first measurements of higher-order light-propagation effects and of the …

it, au, de, us, gb (code pays fourni par la source)

Long-term project observations for project P455 semester 2025OCTS_06

Marta Burgay, Andrea Possenti, Dick Manchester, Michael Kramer et autres

This project is to continue timing and profile studies of the first double-pulsar system, a unique laboratory for gravitational physics. Important results published in our 53-page Phys. Rev. X paper (2021) include the first measurements of higher-order light-propagation effects and of the …

it, au, de, us, gb (code pays fourni par la source)

Exploring Pulsar Timing Precision: A Comparative Study of Polarization Calibration Methods for NANOGrav Data from the Green Bank Telescope

Lankeswar Dey, M. A. McLaughlin, Haley M. Wahl, Paul B. Demorest et autres

Abstract Pulsar timing array experiments have recently uncovered evidence for a nanohertz gravitational wave background by precisely timing an ensemble of millisecond pulsars. The next significant milestones for these experiments include characterizing the detected background with greater precision, identifying its source(s), and …

us, gb, ca, hu (code pays fourni par la source)

Exploring pulsar timing precision: A comparative study of polarization calibration methods for NANOGrav data from the Green Bank Telescope

Lankeswar Dey, M. A. McLaughlin, Haley M. Wahl, Paul B. Demorest et autres

Pulsar timing array experiments have recently uncovered evidence for a nanohertz gravitational wave background by precisely timing an ensemble of millisecond pulsars. The next significant milestones for these experiments include characterizing the detected background with greater precision, identifying its source(s), and detecting …

Comparing Recent Pulsar Timing Array Results on the Nanohertz Stochastic Gravitational-wave Background

Gabriella Agazie, John Antoniadis, Akash Anumarlapudi, Anne M. Archibald et autres

Abstract The Australian, Chinese, European, Indian, and North American pulsar timing array (PTA) collaborations recently reported, at varying levels, evidence for the presence of a nanohertz gravitational-wave background (GWB). Given that each PTA made different choices in modeling their data, we perform …

us, de, gr, gb, in, au, fr, nl, it, cn, ca, pl, jp (code pays fourni par la source)

The NANOGrav 12.5-Year Data Set: Dispersion Measure Misestimations with Varying Bandwidths

Sophia V. Sosa Fiscella, Michael T. Lam, Zaven Arzoumanian, Harsha Blumer et autres

Abstract Noise characterization for pulsar-timing applications accounts for interstellar dispersion by assuming a known frequency dependence of the delay it introduces in the times of arrival (TOAs). However, calculations of this delay suffer from misestimations due to other chromatic effects in the …

us, gb, ca, hu (code pays fourni par la source)

The NANOGrav 12.5 yr Data Set: A Computationally Efficient Eccentric Binary Search Pipeline and Constraints on an Eccentric Supermassive Binary Candidate in 3C 66B

Gabriella Agazie, Zaven Arzoumanian, P. T. Baker, B. Bécsy et autres

Abstract The radio galaxy 3C 66B has been hypothesized to host a supermassive black hole binary (SMBHB) at its center based on electromagnetic observations. Its apparent 1.05 yr period and low redshift (∼0.02) make it an interesting testbed to search for low-frequency …

us, gb, in, ca, de, hu, pr, il, tr (code pays fourni par la source)

The NANOGrav 12.5 yr Data Set: Search for Gravitational Wave Memory

Gabriella Agazie, Zaven Arzoumanian, P. T. Baker, B. Bécsy et autres

Abstract We present the results of a Bayesian search for gravitational wave (GW) memory in the NANOGrav 12.5 yr data set. We find no convincing evidence for any gravitational wave memory signals in this data set. We find a Bayes factor of …

us, gb, ca, de, hu, il, tr (code pays fourni par la source)